Steam-boiler



@Moden J. BARNHART.

STEAM' BOILVER. Y No. 412,718. Patented Oct. 15, 1889.

' UNITED y 4STATES PATENT EEICE.

' JOHN B ARNHART, OF ALTOONA, PENNSYLVANIA. i

STEAM-BOILER.A

SPECIFICATION forming part of Letters Patent No. 412,718, dated October1,5, 1889.

Application filed June 8, 1889. Serial No. 313,542. (No model.)

To all whom it may concern.' f

Be it known that I, JOHN BARNHART, a citizen of the United States ofAmerica, residing at Altoona, in the county of Blair and State ofPennsylvania, have invented certain new and useful Improvements inSteam-Boilers, of which the following is a specification, referencebeing had therein to the accompanying drawing. l

In vertical steam-boilers which are constructed with fines extendingabove the waterline and connected at their upper ends with an upperiiue-sheet an objection exists by reason of the liability of the fluesto become loosened at their connection with the said fine-sheet, thusrendering leakage of steam possible and impairing greatly the use of theboiler. This obj ection arises by reason of the fact that the upperendsof said iiues being above the water-line are not subjected to themodifying iniuence of said water, and thus when the fire is started theheatcauses them to expand quickly at their connection with theiue-sheet, and as said sheet is not acted upon to an equal extent withthe flues the expansion of the latter causesdamage to the joint, andconsequently looseness'- when the parts contract.

The drawing, which' is a vertical central' section, represents a boilerembodying my improvements, the formshown being specially adapted for usewith an engine, though it will be understood that the same featuresareapplicable to all kinds of boilers, such as for house use.

In the drawing, B represents the fire-pot; C, the grate, and a the iiuesfor the products of combustion, ext-ending through the waterspace W andconnected at top and bottom to the line-sheets g andm, respectively.-The. water-space is continued or added to by the water-legs W',extending around the fire-pot and being formed by the shell 1l of saidpot and the outer shell h. The water-line is shown at Z, and the iiues aextend above this to their points of attachment with the upperflue-sheet, and it will be apparent that these upper portions of theiiues will receive the full action of the fire whenit is started, whichaction, being unmodified by the water, will cause said tubes to expandquickly and before the flue-sheet and its supporting-shell are theexpansion is likewise equal.

equally heated, with the effect above stated of causing looseness of`joints. To remedy this, I employ a second set of tubes a to heat theshell which supports the upperflue-sheet and through it the sheetitself, so that the expansion of these parts will be approximately equalto the expansion of the iiues. The shell h', which supports theflue-sheet g, is flaring. It extends below the water-line, and thenhorizontally to provide a supplemental iiue sheet or iiange K, which isconnected to the outer shell h. This iiange receives the supplementalfines c, which are thus shorter than the main fines and below thewater-line. The heating of these tubes, therefore, is modified by thewater throughout. When the fire is started, the heat passes through thetubes a, aswell as through the main tubes a', and the heating of theshell h is simultaneous with and about equal to that of the flues a',and

The steamspace S is heated from the shell as Well as from the tubes,which heat acts upon the flue-sheet to expand the same, and this sheetis also acted upon by the heat from the flues a. A ring 4 is placed uponthe flueflange K, which is -preferably inclined inwardly and upwardly todeflect the heat against the shell h', and to provide a heatingchamberoo with a contracted opening at its upper end. The ring is formed with ashoulder, which receives the dome 3, provided with a damper 6, by whichthe entire draft may be shut off. An inner dome or shell 2. is locatedupon the upper flue-sheet, and this includes only the main flues a. Adamper 5 in this shell serves to shut off the draft from the inner fluesc to any desired extent, leaving the draft through the outer tubesentirely free. By this the burning of the fuel is under more perfectcontrol, as the draft may be regulated and rendered even over the grate.The steam its upper part c, which brings the outer nues o. directly overthe vertical shell of the firepot, so that the draft is provided fromthe circumference of the grate all the way across the same, the draftfrom the outer edge being vertical through the flues a. This alsoprovides a large flue-sheet relative to the diameter of the {ire-pot,and more i'lues may thus be employed. The fire-potis made of a singiepiece of metal, the upper part being ared.

What I claim is- 1. In combination, the fire-pot, the upper and lowerflue-sheets, the main flues a', eX- tending from the lire-box above theWater-line and connected with the upper sheet g, the shell h for theupper flue-sheet, said shell eX- tending below the Water-line, theyflange K, and the series of supplemental tubes a outside the shell h andbelow the water-line, substantially as described.

JOHN BARNHART.

Witnesses:

JOHN CALVIN BARNHART, WILLIAM ATKEN.

